diff options
| author | Suren Baghdasaryan <surenb@google.com> | 2024-07-11 15:04:57 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-07-17 21:05:19 -0700 |
| commit | 6ab42fe21c84d72da752923b4bd7075344f4a362 (patch) | |
| tree | 95f1df4c734dbb0607436085134dd91f64111b63 /include | |
| parent | fd8acc0097b91fab3104fa8a66ce2fd9cf8b0c11 (diff) | |
alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
pgalloc_tag_sub() might call page_ext_put() using a page different from
the one used in page_ext_get() call. This does not pose an issue since
page_ext_put() ignores this parameter as long as it's non-NULL but
technically this is wrong. Fix it by storing the original page used in
page_ext_get() and passing it to page_ext_put().
Link: https://lkml.kernel.org/r/20240711220457.1751071-3-surenb@google.com
Fixes: be25d1d4e822 ("mm: create new codetag references during page splitting")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/pgalloc_tag.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/include/linux/pgalloc_tag.h b/include/linux/pgalloc_tag.h index acb1e9ce7981..18cd0c0c73d9 100644 --- a/include/linux/pgalloc_tag.h +++ b/include/linux/pgalloc_tag.h @@ -71,6 +71,7 @@ static inline void pgalloc_tag_sub(struct page *page, unsigned int nr) static inline void pgalloc_tag_split(struct page *page, unsigned int nr) { int i; + struct page_ext *first_page_ext; struct page_ext *page_ext; union codetag_ref *ref; struct alloc_tag *tag; @@ -78,7 +79,7 @@ static inline void pgalloc_tag_split(struct page *page, unsigned int nr) if (!mem_alloc_profiling_enabled()) return; - page_ext = page_ext_get(page); + first_page_ext = page_ext = page_ext_get(page); if (unlikely(!page_ext)) return; @@ -94,7 +95,7 @@ static inline void pgalloc_tag_split(struct page *page, unsigned int nr) page_ext = page_ext_next(page_ext); } out: - page_ext_put(page_ext); + page_ext_put(first_page_ext); } static inline struct alloc_tag *pgalloc_tag_get(struct page *page) |